@article{CSIS_2021_18_3_a21,
     author = {Zijun Chen and Tingting Zhao and Wenyuan Liu},
     title = {Time-aware {Collective} {Spatial} {Keyword} {Query}},
     journal = {Computer Science and Information Systems},
     publisher = {mathdoc},
     volume = {18},
     number = {3},
     year = {2021},
     url = {http://geodesic.mathdoc.fr/item/CSIS_2021_18_3_a21/}
}